The present invention relates to a heating system, and more particularly to a solar heating system for converting solar energy into the thermal energy of a fluid for heating purposes.
As is well known, solar heating systems generally comprise a heat collector which absorbs energy from the sun and delivers it by way of a heat transfer fluid to a storage unit. In most instances, the heat collector comprises a black plate which absorbs solar radiation, and the plate is usually located within a light-transmitting enclosure. Solar radiation is transmitted through the enclosure to the black plate collector, and the circulating heat transfer fluid absorbs thermal energy from the collector and transfers it to the storage unit for subsequent heating purposes.
One common disadvantage of the heretofore proposed solar heating systems involves the expense of construction materials as well as the expensive techniques used to fabricate the materials into the finished system. Costly materials, such as copper and other conductive metals, are often required. Also, such materials are desirable from the standpoint of resisting damage from the excessive temperature levels generated by solar systems during times of high solar radiation and low heat demand. Less expensive materials, such as thermoplastics and the like, may be readily deformed when subjected to high temperatures of the order generated by solar heating systems during times of high solar radiation and low heat demand, and this factor has discouraged persons from utilizing these materials. In some instances, solar heating systems may be shielded from the sun by intricate shutter arrangements but these constructions are expensive to manufacture and complex in operation. Also, shutters or other types of shielding devices may adversely affect the overall efficiency of the system during its operating mode.